January-February 2009 Issue

	January-February 2009

Reading Smoke, Part 3

By John Mittendorf

IMPORTANCE OF READING SMOKE

The importance of reading smoke can be viewed from three key perspectives as follows:

A. CONDITIONS

Taking the necessary time to read smoke can be an indicator of what is burning, the amount of material that is burning, extension, the resources necessary to extinguish the fire, the potential of flashover conditions, and other pertinent factors. Remember that until a fire within a structure is extinguished, interior conditions will continue to change, and as a rule, not for the better.

B. PERSONAL SAFETY

The ability to read smoke (or the environment) can often yield vital information that enhances the ability of fireground personnel to evaluate two key considerations:

1. Personal Protective Equipment (PPE)

Without a doubt, modern PPE significantly exceeds the capability of the PPE of a few years ago. With the advent of hoods, a firefighter is now fully encapsulated, and the technology (material used for PPE) also exceeds the ability to resist heat far better than the technology of the past. In addition, some firefighters are now equipped with thermal imaging cameras (TIC) molded into their helmets, and “heads-up displays” inside of face pieces that give a visual display from the TIC, and vital information such as how much air is left at the current breathing rate, what is the temperature of the environment around the firefighter, etc. While all of this technology can be beneficial, it can also be detrimental if a firefighter does not have a fundamental understanding of the basics.

As an example, let’s assume that a firefighter is advancing into a structure fire to conduct a search and is experiencing high levels of heat and a lack of visibility. As the firefighter advances into the structure, the TIC display gives a workable picture of the interior contents, the interior temperature, and the remaining air in the SCBA is also clearly visible in the display. Suddenly, the TIC picture, temperature and remaining air display ceases to be visible. Without a basic knowledge of search techniques, safe egress routes, and the ability to evaluate the hostile environment and remaining SCBA air, the firefighter is suddenly faced with a life threatening dilemma that centers on what to do next, and how to do it. Therefore, a crucial question is “how do interior personnel stay aware of changing conditions with or without the advantages of their PPE?”

The moral to this fictional example is a modern firefighter must be able to evaluate changing conditions separate from the protection of PPE that is often taken for granted.

Before the advent of protective hoods and gloves/wristlets, firefighters would constantly be aware of environment conditions by the feedback provided by exposed skin on their hands and ears (this is not to suggest that this method was the most beneficial, but it was fairly accurate). Unfortunately, the advent of gloves, wristlets, and protective hoods eliminated this capability. Now, most firefighters rely on the perceived capability of their PPE.

However, an important characteristic of PPE is that in spite of its protective capabilities, it will allow some heat to pass through the protective layers to the individual wearing the PPE. Interestingly, if a firefighter stays mentally alert to perceived heat levels within PPE, a significant benefit can often be observed. As a general rule, if the perceived temperature is hot enough to be noticed (you are thinking about it), but a firefighter still feels that it is safe to continue to accomplish the intended task, the temperature around the firefighter is approximately 375 to 450-degrees. This is noteworthy from two perspectives:

While continuing to advance into the environment, does the perceived temperature tend to subside, stay the same, or does it appear to increase and by how much?

If the temperature is approximately 375 to 450-degrees, then a great question is “what is the temperature at the ceiling?” The answer to this question can likely be 800 to 900-degrees (which is, or is approaching the temperature favorable to flashover conditions).

If a firefighter maintains a “mental baseline” of the conditions that were encountered when entering the structure (as detailed at the end of this chapter), then the process of evaluating the environment in combination with PPE can be simplified, and provide a measure of safety. Do not “put all of your eggs in one basket.” The fireground definition of this statement is “do not put all of your trust in your PPE, or do not believe what your PPE tells you all of the time”

2. Self Contained Breathing Apparatus

In the early 1960’s, the advent of self contained breathing apparatus gave a firefighter the capability to breath fresh air while exposed to interior conditions encountered during suppression operations. Unfortunately, this advantage was limited by the amount of compressed air in the bottle worn by a firefighter. Today, most SCBA apparatus consists of a bottle charged to about 2,300 psi and rated to last about 30 minutes under ideal conditions. However, it is well known that under stressful working conditions this rated time is in reality about 15-18 minutes.

A dilemma that has plagued the American fire service for decades is the common perception of using “the bottle” until the low air warning device sounds, and in some cases, continuing to use the remaining air to complete a task Regrettably, this can often result in interior personnel not having enough air to safely exit a structure and/or having to breath smoke until being able to exit a structure. As a result of this dilemma, "firefighters that run out of air breath smoke, and firefighters that breathe smoke can die.”

Effective January 2007, NFPA 1404, Standard for Fire Service Respiratory Protection Training, mandates a new focus on the concept of air management. A5.1.4(2) of 1404 deals specifically with an individual air management program that delineates the responsibility of an individual to manage their air consumption during operations in an immediately dangerous to life and health (IDLH) environment. This responsibility is comprised of three primary directives as follows:

Exit from an IDLH environment before consumption of reserve air supply begins
Activation of a low air alarm is a signal that the reserve air is being consumed
Activation of a low air alarm is an immediate action item for the individual and team members

The 1404 standard requires that fire departments train their members to operate in accordance with the Rule of Air Management which states: “know how much air is in your SCBA, and manage that air so that it is possible to leave an IDLH environment before the low air warning alarm activates.” The concept of air management is based on the training and discipline of three basic factors:

First and potentially most importantly, investing appropriate time in training scenarios that allows an individual the opportunity to develop a working knowledge of their air consumption rate and being able to evaluate the amount of air consumed while performing an assigned task in stressful conditions. This also requires that an individual not only monitors their air consumption rate during fireground operations, but also is aware of how much air is left to exit an IDLH in a safe and timely manner
The knowledge of how much air is in an SCBA at the beginning of a tour of duty and prior to entering an IDLH environment
The discipline to balance the amount of air required to perform an assigned task with the amount of air necessary to exit an IDLH environment

Why has NFPA 1404 suddenly become important (and yes, even controversial)? The relevance of 1404 is best understood if we consider the history of SCBA in the American Fire Service. For years, it has been common practice for fireground personnel to use their SCBA in an IDLH environment until the low air alarm activates, and then use two options:

Complete an assigned task under the assumption that it will still be possible to exit the IDLH in a safe manner. While this assumption is dependent upon varying conditions, leaving an IDLH environment with an empty bottle and having to breathe smoke is not an acceptable definition of safe and/or conducive to a healthy lifestyle, particularly an extended healthy lifestyle
Start to exit an IDLH environment. While this option can be successful, it can also lead to insufficient reserve air to safely exit an IDLH in case of an unforeseen problem

Interestingly, the American fire service is likely the only organization that allows personnel in an IDLH environment to use reserve air to continue operating or exiting an IDLH. As an example, the commercial dive industry uses a different set of standards. One-third of the total amount of air is allowed to descend to the desired location, one-third is used for the assigned task, and one-third is used to ascend. However, a diver is expected to end the dive with a minimum air supply of between 500 and 1,000 psi (for a standard 80 cubic foot bottle). If a diver ends a dive with less than 500 psi, insurance claims filed for an injury will not be honored!

As cancer is one of the leading causes of death in the American Fire Service, the importance of managing a limited air supply (the bottle on your back) in an IDLH environment is long overdue.

Note: For more information on this subject, including instructions on how to develop an air consumption rate, the following sources should be required reading: Air Management For The Fire Service, Mike Gagliano, Phil Jose, Casey Phillips, Steve Bernocco, Fire Engineering Books and Videos; and Air Management: Know Your Air-Consumption Rate, Mike Gagliano, Phil Jose, Steve Bernocco, Casey Phillips, Fire Engineering, October 2006.

C. ASSIGNMENT

Although every firefighter assigned to fireground operations should understand the importance of reading smoke, the need to read smoke from a truck company point of view should be a basic necessity. Although the reason for this statement should be obvious for the reasons previously listed under the sections Conditions and Personal Safety, there is another less obvious reason — lack of protection! In many cases, engine company personnel have a charged hose line during the extinguishment phase of fire suppression operations. This affords some degree of protection if the environment suddenly changes and becomes an immediate threat.

Conversely, truck company personnel (or personnel assigned to truck company operations) can be engaged in interior operations that do not normally require a charged hose line (i.e., search). Therefore, it is possible for truck company personnel to be placed in a difficult situation if the interior environment suddenly changes and becomes an immediate threat, and a measure of protection (charged hose line) is not readily available. This is a prime reason why it is even more important for truck company personnel to read the smoke, and, ensure that forcible exit has been completed.

Additionally, PPE has advanced to the point that firefighters are over-protected due to the ability of PPE to mask or shield a firefighter from the environment, giving a false impression of safety. This statement asks a pertinent and practical question: “Do you take advantage of your PPE or does your PPE take advantage of you?”

Chief Mittendorf is the author of Truck Company Operations and Facing the Promotional Interview. To purchase, return to the Main Page and scroll down to Fire Nuggets Books and Videos.

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